SANTA CLARA -- The train story is a good story. Jim Harbaugh used the analogy after the 49ers' cinematic and splendiferous victory over the New England Patriots on Sunday night.

The coach explained that when he played for the Chicago Bears, he lived in a suburban apartment by the Deerfield train station. At first, the noise was noticeable and irksome. But after a while, Harbaugh didn't notice it anymore.

"It's like, the more you hear the train, the less you hear it," he said. "I feel that way with our team in terms of pressure in big games. The more you hear it, the less you hear. The more you feel it, the less you feel it."

Good thing. Because the train noise will be even louder next weekend. The 49ers' game at Seattle on Sunday is bigger than the game at New England was.

You don't think so? Oh, I realize that the 49ers-New England matchup was supposed to be the most epic event in the history of the free world. But when you consider all the factors, beating Seattle is more paramount.

To be sure, the 49ers can lose Sunday and still clinch the NFC West championship by beating Arizona at Candlestick Park on Dec. 30 in the final regular-season game. But the goal for Harbaugh's team is far, far beyond a mere division title.

You could sense that Monday during Harbaugh's media session. Asked to elaborate on the train analogy, he spoke with pride of how locked in his players seemed to be during both the ups and downs of the rainy, sleety night in New England. Harbaugh does not often open up about his internal dialogue. But this time, he did.

"You think back during that game," he said, "and it just hit me that there's never a time with our team that you see the evidence it's getting to them or that they're pointing fingers at each other. And that's so easy to do. I mean, accountability for a lot of people is just naming names. His fault, his fault, his fault ... Why didn't you do this or do that? ... I never see that with our team.

"We have excellent players who are kind of in the prime of their career. They're at the experienced height, but they're young, and they've been in those situations. They're young, experienced and kind of right in their prime."

Perhaps that was not a blatant and official declaration for Super Bowl candidacy. But it was in the same area code.

Which is fine. The 49ers are a potential Super Bowl team and shouldn't be shy about saying so. History shows, however, that the easiest way to reach the game is by finishing with a top-two seed in the conference and earning a first-week playoff bye -- which makes it possible for a team to reach the Super Bowl by winning just two postseason games instead of three. Every opponent in the playoffs is tough. So avoiding an extra meat grinder is preferable.

Hey, math doesn't lie. The last 10 Super Bowls featured 20 teams. Thirteen of those 20 got there after earning first-week byes.

The 49ers currently are seeded second in the NFC, with Green Bay just half a game behind and pressing. A loss by the 49ers at Seattle on Sunday, combined with a likely Packers victory over Tennessee, would put the Packers in the second spot heading into the season's final week.

Thus, the Seattle showdown, which is conveniently scheduled two days after the Mayan forecasters are predicting Armageddon. The 49ers have showed us much good stuff over the past two seasons. But asking them, just seven days later, to ramp up again on the road and hit the same intensity level they attained in New England ... it's no given.

"This game will be the same, I really believe that," Harbaugh said, acknowledging that the Patriots game was a draining experience and that he might take it into account by dialing back some of the practice physicality this week.

"I think it's something to take a look at and probably implement," Harbaugh said.

For at least one key player, there won't be a choice. Justin Smith, who is both the Washington Monument and Lincoln monument of the 49ers' defensive line, sustained an arm injury at New England that makes his status uncertain for Seattle. Harbaugh conceded that when Smith left the game in the second half, it affected the defense's ability to thwart the Patriots' 28-point comeback.

If Smith can't play against the Seahawks, his leadership will be missed as much as his football skills.

On offense, it would be nice to see Mario Manningham back in the lineup at wide receiver. But he also is iffy. Heck, every 49er is probably sore somewhere. It is why getting that extra week off in the playoff tournament can be so crucial.

Could the 49ers still reach the Super Bowl as a third or fourth seed? Sure. The New York Giants did it as a sixth seed last year. If a team from a wild-card round reaches the game, it often performs well. Probably, that's because of the traditional extra week between the conference title games and the Super Bowl. It puts the two competing teams on more equal footing.

Still, forever and always, getting to the Super Bowl is the hardest part. And it is much easier with a first-round bye. Any serious 49ers historian should knows this. Remember the franchise's five Super Bowl champions from back in the day? Remember how many of those teams reached the game without a bye in the wild-card round?

The correct answer is none. All five avoided it. Winning in Seattle might be technically optional. For a genuine Super Bowl candidate, it is all but compulsory. And bigger than New England.

Contact Mark Purdy at mpurdy@mercurynews.com. Follow him on Twitter at twitter.com/MercPurdy.

Sunday's game

49ers (10-3-1) at Seattle (9-5),
5:20 p.m. NBC


INSIDE

Harbaugh notes intensity in win over Patriots

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49ers grades.

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